json字符串出现转义符，导致调用者使用ObjectMapper解析成Map报错

json1串：

{"orderCount":0,"signType":"SHA256WithRSA","sign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returnCode":"1","returnDesc":"系统执行错误"}

json2串：

"{\"orderCount\":0,\"signType\":\"SHA256WithRSA\",

\"sign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returnCode\":\"1\",\"returnDesc\":\"系统执行错误\"}"

报错内容：

Can not instantiate value of type [map type; class java.util.LinkedHashMap, [simple type, class java.lang.Object] -> [simple type, class java.lang.Object]] from JSON String; no single-String constructor/factory method

原因：

使用中涉及如下两个方法：

public void sendText(HttpServletResponse response, String str)
throws IOException {

// 必须写上这句，中文编码问题
response.setContentType("text/plain;charset=UTF-8");
//response.setContentType("application/json;charset=utf-8");

response.getWriter().write(str);
response.getWriter().flush();
response.getWriter().close();
}

public void sendResponse(HttpServletResponse response, Object object)
throws IOException {
logger.debug("响应的对象:{}", object);
Gson gson = new Gson();
String respJson = gson.toJson(object);

logger.debug("响应的数据:{}", respJson);
logger.debug("响应的状态:{}", response);
sendText(response, respJson);
}

首先我将上述json1字符串传入sendResponse方法，其内部会对json1字符串再做一下json转换，此时得到json2串，即带有转译字符。

调用者获取json2串使用ObjectMapper转换成Map便会报上述错误。

解决方法：

     直接调用sendText方法发出响应。